Iran has notified the International Atomic Energy Agency (IAEA) about the construction at the Fordow nuclear facility, Iranian Foreign Ministry spokesman Saeed Khatibzadeh said on 21 December.

"There is nothing new, all actions are under the supervision of the IAEA. We have informed the agency, there is nothing secretive about this,” he told a briefing. 

This followed the publication by Associated Press on 18 December of satellite photos from Maxar Technologies that show that construction had resumed at the Fordow underground nuclear facility.

The suspension of uranium enrichment at Fordow was one of the conditions of the July 2015 Joint Comprehensive Plan of Action (JCPOA) between Iran the P5+1 group of countries (the USA, UK, France, Russia, and China plus Germany) under which Iran had agreed to limit its nuclear development programme in return for the lifting of sanctions. In response to the US withdrawal from the deal in 2018, however, Iran resumed enriching activities at Fordow, having previously told the IAEA it would do so.

In November, the Iranian parliament passed a bill, 'The strategic measure for the removal of sanctions,' ordering the revival of nuclear activities in the wake of the assassination of Iranian nuclear physicist Mohsen Fakhrizadeh. Following the US Presidential election, however, there are hopes that the USA may rejoin the JPCOA. President elect Joe Biden has said the USA will rejoin the deal “if Iran resumes strict compliance” with the agreement. Iran has consistently said that, in this case, it would immediately roll back its nuclear development in line with the original restrictions.

On 17 December, however, IAEA Director General Rafael Grossi suggested that this may involve a new agreement setting out how Iran’s recent activities should be reversed. In an interview with Reuters, he said there had been too many breaches for the agreement to simply fall back into place.

“I cannot imagine that they are going simply to say, ‘We are back to square one’ because square one is no longer there,” Grossi said. “There is more (nuclear) material, … there is more activity, there are more centrifuges, and more are being announced. So what happens with all this? This is the question for them at the political level to decide.”

He added: “It is clear that there will have to be a protocol or an agreement or an understanding or some ancillary document which will stipulate clearly what we do.”

On 21 December, Khatibzadeh said Grossi’s remarks had been misinterpreted. “We have maintained that the JCPOA is not open to negotiation and no document can be added to the deal."

Khatibzadeh stressed that Iran’s ties with the IAEA are technical and that the ties must be maintained within the same technical framework.

“Indeed, the ties have always been clear, transparent and pragmatic whenever the IAEA had a totally technical view of issues,” he added. “We have always advised the IAEA to stay away from political issues, political pressures and certain moves by third parties in order to maintain the weight, credibility and dignity of the IAEA and to keep its ties with Iran in the path of technical cooperation,” he said.

Following an online meeting of Iran and P4+1 foreign ministers on Monday, Iran's Foreign Minister Mohammad Javad Zarif  said on Twitter it was the last chance for E3/EU to save the JCPOA.

He said that Iran-EU 2014-2019 trade data "proves E3/EU have gravely breached their JCPOA obligations" and that "E3 share the blame with US for irreparable harm to Iranians."

"ALL must return to effective JCPOA compliance. Iran will rapidly reverse remedial measures in response to US unlawful withdrawal—and blatant E3 breaches—when US/E3 perform their duties. The Iranian people MUST feel the effects of sanctions lifting," he tweeted.